Is the Texture Coordinate node currently broken for vector displacement?
As always, open to correction, but reverse-engineering from the symptoms alone, this seems to be a caching problem.

If you plug the displacement vector straight into the Displacement
input of a Material Output node, the vector seems to be evaluated in World
space.
If you request a displacement in World space (however it is calculated,) you would expect an object to 'swim' through that displacement when it is rotated: in the viewport, it does not. The displacement appears to be cached in Object space. When the object is transformed, the displacement follows.
You can update the cache in at least two ways I've found.. flip out of Rendered to Solid mode and back again, or put a Vector Displacement node between the requested vector and the  Material Output, and switch its space from, say, 'World' to 'Object' and back again.

The cache appears only to apply in the viewport: in frames rendered through a camera the displacement is updated correctly.
I think this may qualify as a bug..or it may considered a valid optimisation for viewport performance?
TL;DR
To evaluate the displacement vector in Object space, (so it follows the object, and therefore persists through flipping between Rendered and Solid modes), put it through a Vector Displacement node, set to 'Object Space'.